A known embodiment of a reactor for entrained flow gasification has a common reactor outlet for molten slag and the hot crude gas (see FIGURE, reference symbol 5) into the quench chamber. The hot crude gas is rapidly cooled off there by the injection of water. The molten slag simultaneously solidifies and falls into the quench chamber sump. The protective slag discharge tube (also called the draft tube) located at the outlet of the reactor has the task of protecting the slag discharge against direct contact with quench water to prevent the slag solidifying and thereby to prevent a blockage of the reactor discharge outlet. This protective tube is subjected to high thermal stresses and thereby to high levels of wear. In particular when short-duration buildups of slag deposits divert the stream of crude gas heated up to between 1300° C. and 1800° C., damage to this protective tube can result.
The thermal stress on the protective slag discharge tube was previously countered by an intensive cooling down with cooling water. This cooling facility contains the double-wall version of the protective tube, the inclusion of cooling water lines in the quench chamber and the establishment of a cooling water circuit with the corresponding armatures and volume measurement facilities.